Addition rearrangement products of thiocyanic acid and cyclopentadiene-olefinic adducts



Patented Dec. 3,. 1946 ADDITION REARRANGEMENT PRODUCTS OF THIOCYANICACID AND CYCLOPENTA- DIENE-OLEFINIC ADDUCTS Herman A. Bruson,Philadelphia, Pa.-, assignor to The Resinous Products & ChemicalCompany,

Philadelphia, Pa., a corporation of Delaware I No Drawing. ApplicationOctober 6, 1944, 1 Serial No. 557,554

6 Claims.

This invention relates to addition-rearrangement productsof thiocyanicacid and cyclopentadiene-mono-olefinic adducts.

Thi'ocyanation of organic compounds has heretofore been accomplished byreplacement of a halogen atom or a sulfate or phosphate ester group byreaction with a salt of thiocyanic'acid, or by addition of 'thiocyanogento both sides of a multi-bonded linkage of carbon atoms, or by additionof thiocyanic acid to certain unsaturated hydrocarbons having reactivedouble bonds;

whereln there are used inert, anhydrous organic solvents at relativelylow temperatures and where no rearrangement of the hydrocarbon occurs.It

has been gen'erally'held impractical to work with thiocyanic acidbecause it readily polymerizes at room temperature or in aqueoussolutions to a yellow insoluble compound. For this reason it can behandled only in dilute, inert, anhydrous solutions; for example; ether,at ice bath temperatures, and gives very poor yields of product.

In accordance with the present invention, however, it has been foundthat by operating under conditions contrary to the prior art; namely, in

the presence of water and at elevated temperatures,cyclopentadiene-mono-olefinic adducts can be reacted smoothly withthiocyanic acid to form good yields of new hydrothiocyanates andisothiocyanates in which a rearrangement of the initial ring system hasoccurred. By operating at temperatures from about 30 C. to 100 C. and

in the presence of water, the rate of addition of the thiocyanic acid tothe double bond is apparently greater than the rate of polymerization ofthe thiocyanic acid itself. Furthermore, the products obtained as aresult of the reaction are not simple addition products per se formed bythe addition of thiocyanic acid to. the double bond, but are molecularrearrangement products formed by a rearrangement of the ring. It isremarkable that even at 90 C.-l C. and in the presence of water onlytraces of polythiocyanic acid are encountered and that even in thosesuch as calcium thiocyanate, or ammonium thiolimate.- One or more ofsuch salts may be used over a wide range of concentration- Dilutesolutions up to super-saturated solutions may be employed.

To liberate thiocyanic acid from these salts, there may be usednon-oxidizing mineral acids over a considerable range of concentration.Acids such as hydrochloric, sulfuric, and phosphoric are particularlysuitable and may advantageously be used at concentrations from 10% toabout 40% although weaker and more concentrated solutions are alsouseful. The acid and thiocyanic acid salt are desirably used inequivalent proportions.

Incarryingout the reaction, the salt and acid are graduallycombined ormixed in the presence of water and in the presence of the cyclopen- Thetadiene-monoolefinic adduct employed. latter may be stirred with anaqueous solution of the salt, and the acid added thereto little by lit-"tle-.. Onthe'other hand, the salt ora solution or a suspension thereofmay be added gradually to .a stirred mixture of the acid and the cyclo-.pentadiene-mono-olefinic adduct. The latter may also be added directlyto a solution of the mineral-acid or of the thiocyanate salt in water orin a mixture of water and an organic solvent, particularly one misciblewith water such as acetone or ethyl alcohol. Or thecyclopentadienemono-oleflnic adduct can be dissolved in awaterimmiscible solvent such as benzene, the finely powdered thiocyanatesalt added thereto, and the mixture rapidly stirred while an aqueoussolution of the mineral acid is gradually added thereto. This isparticularly useful if the olefinic compound is a solid or is highlyviscous.

According to this invention, there is thus liberated atany given momentonly a relatively small amount of thiocyanic acid in a reaction mediumcontaining water and the cyclopentadiene-mono-olefinic adduct with orwithout the presence of an'organic solvent, at a temperaturesufllciently high for the desired addition and rearrangement to occur asrapidly as the thiocyanic acid is formed, thereby practicallyeliminating the polymerization of the latter. For this purpose areaction temperature between about 45 C. and C. has been found mostadvantageous.

The process disclosed herein is applicable to a wide variety ofcyclopentadiene-mono-oleflnic adducts of the Diels-Alder type. Forexampl the process is applicable to the Dials-Alder type adducts ofcyclopentadiene and the following mono-olefinic compounds; thatis,compounds having an open-chained group containing a double bondedlinkage between carbon atoms:

Ethylene, propylene, styrene, pl-bromostyrene, ally] alcohol, allylchloride, vinyl chloride, vinyl acetate; allyl esters such as allylacetate, allyl oleate, allyl benzoate, allyl salicylate; allyl ethers,for example ally] phenyl ether, allyl naphthyl ether, allyl chlorophenylether, allyl cyclohexyl ether, allyl benzyl ether, allyl benzyl sulfide,allyl butyl sulfide; 1,2-dichloroethylene, allyl benzene,

eugenol, safrol, croto'naldehyde, acrolein, methyl vinyl ketone, andother zip-unsaturated aldehydes-or ketones.

The products are useful as toxicants for the preparation ofinsecticides. They also possess parasiticidal activity.

In order to illustrate this invention more fully, the following examplesare given.

Example 1 To a rapidly stirred mixture consisting of '46 g. of ammoniumthiocyanate, 48 g. of'water, and 62 g. of 2,5-endomethylene-A-tetrahydro-benzyl alcohol (cyclopentadiene-allyl alcohol adduct) therewas gradually added dropwise 60 g. of concentrated 35% hydrochloric acidduring the course of twenty minutes while the reaction temperature wasmaintained at 40 C.-45 C. by means of a warm water bath. After all thehydrochloric acid had been added, the mixture was stirred for one hourlonger at 40-45 C. and allowed to stratify. The oil layer was separatedby means of a little benzene and the benzene solution washed thoroughlywith water, filtered from traces of polythiocyanic acid, dried, anddistilled in vacuo.

The product boiling at 169-172 C./6 mm. was a colorless oil having theproperties of a saturated thiocyanate and of the correspondingisothiocyanate, indicating that the product is a mixture of thiocyanateand isothiocyanate, of the probable formula JNS) Example 2 I Twenty-fivegrams of concentrated hydrochloric acid was added dropwise during thecourse of ten minutes to a rapidly stirred mixture of 20 g. of water, 20g. of ammonium thiocyanate, and 38 g. of 2,5endomethyl-M-tetrahydrobenzyl acetate on CH-O-C o-cm which is obtainedby reacting cyclopentadiene with vinyl acetate, The reaction mixture wasmaintained at -95 C. during the addition of the hydrochloric acid andfor twenty-five minutes thereafter. The product was washed with water,

filtered, and dried. The clear oil obtained was then distilled in vacuo.

The product boiling at 155-160 C./7 mm. was a colorless oil,corresponding in composition with compounds of the probable formula CH-\CH| l l H,- l (oNs) Example 3 To a rapidly stirred mixture of 50 g. ofwater, 48.5 g. of sodium thiocyanate, and 92 g. of 2,5- endom'ethylene Atetrahydro benzylphenyl ether when heated with concentrated ammoniumhydroxide solution, it yields the corresponding thiourea as acrystalline compound, melting at 135 C.

The 2,5-endomethylene-n -tetrahydro-benzylphenyl ether used is acolorless oil boiling at 133-136 C./6 mm. obtainable by boilingdicyclopentadiene with allyl phenyl ether.

Example 4 To a rapidly stirred mixture of 35 g. of water, 32.4 g. ofsodium thiocyanate and 70.4 g. oi 2,5- endomethylene Atetrahydrobenzyl-o-chlorophenyl ether maintained at 95 0., there wasadded dropwise 40 g. of concentrated hydrochloric acid during the courseof ten minutes. The mixture was then stirred for one hour longer at 95C. It was l ml -63 The 2,5-endomethylene-A-tetrahydro-benzylo-chlorophenyl ether used is a colorless oil boilingat 130-.134 c./1 mm. obtainable by boiling dlcyclopentadiene withallyl-o-chlorophenyl ether.

Example 5 A mixture of 104 g. of dicyclopentadiene and 183 g. ofallyl-p-(a,amr-tetramethyl-butyl)- phenyl ether was boiled under areflux condenser at 160-175 C. for eight hours, and the product thendistilled in vacuo. The compound having the formula was obtained as acolorless oil boiling as 167-- 172 C./1-2 mm. in a yield of 125 g. Thedicyclopentadiene in this preparation apparently depolymerizes to supplycyclopentadiene which forms the adduct as indicated. This method offorming intermediates is a particularly useful and advantageous one. v

The above compound (94 g.) was rapidly stirred with 35 g. of water and32.4 g. of sodium thiocyanate at 95 C. while 40 g. of concentratedhydrochloric acid was added dropwise thereto during the course of twentyminutes. After all the acid had been added, the mixture was stirred forone hour longer at 95 C., then cooled, taken I Ezample a To a rapidlystirred mixture of 56.7 g of sodium thioeyanate, g. of water, and 124 g.of 2,5- endomethylene-A -tetrahydro-benzylbenzoate E LJi F f maintainedat 95298? 0., there was added drop taken up in benzene.

6 wise g. of concentrated hydrochloric acid during the course of twentyminutes. The mixture was then stirred ten minutes longer at (2., cooled,mixed with 500 cc. of waterand the oil The benzene layer was filtered,washed, dried, and distilled in vacuo.

The product boiling at 215 C./1 mm. was a viscous, pale yellow oilhaving the properties of an isothiocyanate of the probable formula on clcn, l H] l m-l- -cm-o-co- N=C=S The yield of .product amounted to grams.

Example 7 A mixture of 324 g. of safrol (2 mols) and 139 g. ofdicyclopentadiene (1 mol) was heated under a reflux condenser at 160-170C. for fifteen hours and the product then distilled in vacuo.

The desired product having the formula distilled over at -145 C./34 mm.as a viscous, pale yellow oil in a yield of 180 g. The purecompoundboiled at -140 C./2-mm.

To a rapidly stirred, heated mixture of the above cyclopentadiene-safroladduct (91 g.), 40 g. of water, and 40.5 g. of sodium thiocyanate,maintained at 95 (2., there was added dropwise 50 g. of. concentratedhydrochloric acid (35%37% HCl) during the course of ten minutes. Themixture was stirred at 95 C. for one hour after all the hydrochloricacid had been added. The oily reaction product was taken up in benzene,the benzene solution filtered'and then washed several times with water,dried, and distilled in vacuo.

The fraction boiling at 220"-230 CJZ mm. was

a viscous, pale yellow oil. The yield was 86 g. Upon redistillation, itboiled at 214-'216 C./1

'mm. The compound is an isothiocyanate having the probable formula CH clcm o l H: i I v C Hl H,- -cn;- o

1i=c=s Example 8' Amixture of .201 g. of fl-bromostyr ene and 83.4 g.-ofdicyclopentadiene washeated under reflux at -165 C. for seven hours,andthe product distilledln vacuo, resulting I in aQcompound having theformula which boiled at 131"7-140 C./6-7 mm. It was'a pale yellow oil.The yield was 80 g.

A mixture consisting of 50 g. of the above compound, 24.3 g. of sodiumthiocyanate, and 25 cc. of water was rapidly stirred and heated to 95 C.To the'stirred, heated mixture, 30 g. of concentrated hydrochloric acidwas added dropwise on I Example 9 A mixture of 139 g. ofdicyclopentadiene and 190 g. of allyloxydihydronordicyclopentadienewasheated at 165-l75 C. for ten hours under reflux condenser and theproduct distilled in vacuo.

The compound having the formula on on on, o l om ol o cn E i 1 i i n la-om-o- H-- H C I distilled over at 145-150 C./l mm. as a colorless,viscous oil.

A rapidly stirred mixture of 58 g. of the above compound, 24.3 g. ofsodium thiocyanate, and 25 g. of water was treated at 95 C. with 30 g.of concentrated hydrochloric acid, added dropwise during fifteenminutes. The mixture was then stirred for forty minutes at 95 C. anddiluted with 500 cc. of water. The oil layer was taken up in benzene,filtered, washed, dried, and distilled in vacuo. The product boiling at197-203 C./1 mm. was a viscous, pale yellow oil havin the properties ofan isothiocyanate of the prob- Example 10 A mixture of 46g. ofdicyclopentadiene and 78 g. of allyl trichloro-(2,4,5) -phenyl ether washeated under reflux at 160-l65 C. for eight hours and the productdistilled in vacuo.

was obtained as a colorless, viscous oil boiling at 155-160 C./1 mm.

A stirred mixture of 40 g. of the above 2,5.- endomethylene Atetrahydro-benzyl-trichlorophenyl ether, 16.2 g. of sodium thiocyanate,and 17 g. of water was treated dropwise at -98 C. with 20 g. ofconcentrated hydrochloric acid during the course of thirty minutes. Themixture was then stirred one hour longer at 95 C. and worked up as inExample 8.

The product boiling at 235-240 C./1 mm. was a very viscous, pale yellowoil having the properties of an isothiocyanate of the probable formulaor: c| cm' 01 l on, J} v m-I- -c1zr-o 01 1 1 N=C=S Example 11 A mixtureof 104 g. of styrene and 139 g. of dicyclopentadiene was heated underreflux in the presence of 5 g. of phenyl-p-naphthylamine for seven hoursat -170 C., and the product distilled in vacuo.

The desired product having the formula Cafes was ,was obtained, as apale yellow oil boiling at 159-160 C./0.5 mm., in a yield of 77 g.

. Example 12 A mixture of 86 g. of dicyclopentadiene and 1'73 g. of5-ethyl-3-heptene-one-2 was boiled under reflux at l62-172 C. for sevenhours and the 9 product distilled in vacuo. The

compound having the formula I L H-C -CH: distilled over 8,1} IMP-120C./-6 mm. as a colorless liquid.

A mixture of 59 g. of the above compound, 28.3 g. of powdered sodiumthiocyanate and 100 g. of benzene was rapidly stirred at 80-85 C. while35 g. of concentrated hydrochloric acid was added dropwise theretoduring the course of fifteen minutes. The mixture was stirred for onehour longer at the boiling point, then washed, filtered, dried, anddistilled in vacuo.

The product boiling at l'70-l'l4 C./1 mm. was a viscous, pale yellow oilhavirfg the properties of 7 an isothiocyanate of the probable formulaExample 13 A mixture of 200 g. of eugenol and 169. g. ofdicyclopentadiene was heated under reflux for fourteen hours at 160-l65C. and the product distilled in vacuo.

The desired compound having the formula distilled over at 147-150 C./1mm. as a pale yellow oil which solidified toa? crystalline mass.

Concentrated hydrochloric acid (30 g.) was added dropwise to a rapidlystirred mixture consisting of 48.5 g.f of theabovecyclopentadieneeugenol adduct, 50 cc. of benzene, 25 cc. of water, and24.3 g. of sodium thiocyanate maintained at 85-90 C. The mixture washeated for hour longer at 85 C.. then filtered, the benzene solu- O OH:

- tion' washed;dried, and distilled in vacuo.

The isothiocyanate having the probable formula boiled at 215 211; c. 1,mm. It was 9, ve

thick oil.

Example 14.

To a rapidly stirred, heated mixture of 40.5 g.

oi sodium thiocyanate, 50 g. of water, 50 g. of benzene, and 55 g. of2,5-endomethylene-A -tetrahydrophenol I orr cfl$cm Hr l Example 15 To astirred mixture of 30 g. of ethanol, so g.

of water, 28 g. of sodium thiocyanate, and 61.3. of 2,5-endomethylene Atetrahydro dibenzyl ether Cara.

maintained at 90 C. there was added dropwise 35 g. of concentratedhydrochloric acid during the course of twenty minutes. The mixture wasthen stirred thereafter for one and one-half hours at 90 C. and finallywashed, filtered, dried, and distilledinvacuo. J

The product boiling at 184-186 C./1.5 mm. was a pale 'yellow oil havingthe properties of an isothiocyanate of the probable formula on cg i omad -D" i r=c=s The 2,5-endomethylene-M-tetrahydro-dibenzyl ether usedabove is a colorless liquid boiling at 114-118 C./0.5 mm. obtainable byboiling dicyclopentadiene with allyl benzyl ether;

Example 16 v I A mixture of 113 g. of benzyl allyl sulfide .and

96 g. of dicyclopentadiene'was heated six hours at '16 O-1'l0 C. and theproduct distilled in vacuo.

' The compound boiling at l40-l50 C./1-2 mm.

having the formula H-CHrB-oIr G 5 I was obtained as a pale yellow oil.

A mixture of 40 g. of the above compound. 40 g. of benzene, 40 g. ofwater. and 16.2 g. of sodium thiocyanate was stirred rapidly at 84 C.

while 20' g. of concentrated hydrochloric acid was added dropwise duringfifteen minutes. The

cn cg cm CH1 i=e=s Example 17 A mixture of 136 g. of 2,5-endomethylene-Atetrahydro-6-methyl-benzaldehyde.

CH H-CHO Example 18 A mixture of 40 g. of 2,5-endomethylene Atetrahydrobenzyl-sec, octyl ether.

CH C l \CHI CH: CH: CH I CH-CHr-O-(JH-(CHah-CH:

40 g. of benzene, 20 g. of water, and 16.2 g. of sodium thiocyanate wasrapidly stirred at 83 C. while 20 g. of concentrated hydrochloric acidwas added dropwise during ten minutes. The mixture was then stirred onehour longer at 83 0., filtered, the benzene layer separated, washed,dried, and distilled in vacuo.

The product boiling at 185-190 c. 2 rnm.

was a pale yellow oil amounting to 30 g. which, upon redistillation,boiled at 170-172 C./1 mm. and possessed the properties of anisothiocyanate of the probable formula Example 19 Fifty grams ofconcentrated hydrochloric acid was added dropwise during one hour to astirred boiling mixture of 90 g. of benzene. 4.1 3. of

12 sodium thiocyanate, and 88.5 g. of 2,5-endometh-- ylene-A-tetrahydro-benzyloxypropionitrile The mixture was stirred 30 minuteslonger at the boiling point, then filtered and washed several times'withwater, dried, and distilled in vacuo.

The product boiling at 195-205 C./1 mm. was a colorless oil weighing 70grams which gave tests for an isothiocyanate of the probable formulaUpon redistillation, the pure compound boiled at 200-205 C./1 mm.

0 The 2,5-endomethylene-A -tetrahydro-benzyloxypropionitrile used aboveis a colorless oil boiling at 104-108 C./12 mm. obtained by heatingdicyclopentadiene with B-allyloxypropionitrile.

The products of this invention are isothiocyanates or mixturescontaining said isothiocyanates in which the isothiocyanate group isdirectly attached to a carbon atom of the saturated and rearranged ringobtained from the original cycle of the cyclopentadiene.

I claim:

1. A method for preparing addition-rearrangement products of thiocyanicacid and cyclopentadiene-mono-olefinic adducts, which comprises reactingsaid adducts with thiocyanic acid in the presence of water, thethiocyanic acid being gradually liberated in the reaction mixture by theactionof a non-oxidizing mineral acid upon a salt of thiocyanic acid.

2. As new compounds, the reaction products ob- 5o tained by the additionof nascent thiocyanic acid in an aqueous medium tocyclopentadiene-monoolefinic adducts with consequent rearrangement ofthe ring system of said adducts, said products comprisingisothiocyanates in which the isothiocyanate group is directly attachedto a carbon atom of the saturated, rearranged ring obtained from thecyclopentadiene.

3. M newcompounds, addition-rearrangement products of thiocyanic acidand substances having the formula wherein R is an aromatic hydrocarbonnucleus, said products being isothiocyanates in which the isothiocyanategroup is directly attached to a carbon atom of the saturated andrearranged ring obtained from the cycle supplied by cyclopentadiene inthe preparation of said substances.

7o 4. As a new compound, an addition-rearrangement product, ofthiocyanic acid and a substance 6. As a. new compound, anaddition-rearrange having the formula ment product of thiocyanlc acidand a substance H having the formula c cm 6 L f ig csom fli snn-czu-oCF-ox said'compound being an isothiocyanate. 10 v 5. As a. newcompound, an addition-rearrange-j i ment product of thiocyanic acid anda substance Sam compound be us an isomocyanatehaving the formula vHERMAN A. BRUSON.

OH I 0 I cm fl glwojl:

said compound being an isotluocyanate.

